This invention relates to a marker light used for airports and general roads.
The marker light which is installed at airports and the like usually has an optical system comprising a light source lamp, a reflector for forwardly reflecting light emitted from the light source lamp and a prism or a lens for controlling light from the reflector through a filter, and these component parts are progressively accommodated in an optical system casing having a sealed structure. In these prior-art marker lights, however, only the light source lamp and reflector are fixed on a base, with the other components made of glass are directly secured to openings or windows formed in the casing made of a casting of iron, aluminum or the like. Therefore, the characteristics of the optical system cannot be grasped before it is completely assembled, and the adjustment requires troublesome steps of disassembling the casing, carrying out adjustment of the individual component parts and confirming the adjustments after the system is reassembled.